5d Mark III low iso poor performance.

Started Jun 20, 2012 | Discussions thread
gigamel Regular Member • Posts: 178
Re: You dont need Sony-Exmor tech to have clean shadows

schmegg wrote:

gigamel wrote:

"according to DXO, slightly less noise at all ISO's than the D700 and all but exactly the same noise as the D800."

Because the DxO "noise" you are talking about is SNR18 - do you know what that means? Guess not!

It means the signal to noise ratio at 18% middle gray - that is smack in the middle of the histogram and has nothing to do with the noise in the shadows!!

It does however represent an image level measurement of noise - much more useful in practical terms when you are interested in creating images rather than measuring parameters - something that certainly seems to escape you.

Here is the DxO graphs for image level SNR ...

Remarkably - these lines, or rather, the difference between them quite accurately represents the amount of difference you'll see in noise in the images from these cameras when the image has been exposed properly. It also accurately represents the difference in images you'll see on sites that actually test these cameras - rather than just measuring sensor parameters.

Now - if you are the type that regularly underexposes your subject by, say, 4 stops, then the difference in shadow performance might be important. But, fortunatley for most of us (though sadly not yourself it would appear), we manage to expose our subject much more accurately and effectively than that!


You only photograph grey cards????????
ALL your pixels are exposed to 18% middle grey???????


ALL normal images contain a variety of grey levels!!!

Take a look at your histograms!!!


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